[2] Development of the RAK dates back to the late 1950s when the concept was first proposed at the Warsaw University of Technology in response to a requirement for a light hand-held defensive weapon for rear-echelon soldiers such as gun crews and vehicle drivers.

After the death of the chief designer Piotr Wilniewczyc in 1960, the submachine gun’s development was eventually resumed and completed by the state-operated Łucznik Arms Factory in the city of Radom, where it was produced until 1977.

A slightly modified, unlicensed version of the PM-63 was produced by the People’s Republic of China as the Type 82, who sold the weapon to politically allied nations in Asia.

When the trigger is pulled the slide is released and driven forward by the return spring, stripping a round from the magazine and feeding it into the chamber.

The slide houses an inertia buffer and spring retarder mechanism, designed to reduce the weapon's rate of fire down to 650 rounds/min from a natural frequency of about 840 rounds/min.

[citation needed] A spring-loaded extractor is installed inside of the slide and a raised side wall of the seated magazine acts as the casing ejector.

[citation needed] The retractable metal stock (made from strips of flat bar) is ended with a pivoting shoulder pad.

The weapon’s barrel, which can be removed by the operator in field conditions has a chrome-lined bore and 4 right-hand grooves with a 1 in 252 mm (1:10 in) rifling twist rate.